Creating a Custom PHP_CodeSniffer Rule to Disallow Hash Comments

After learning the basics of lexical analysis, we demonstrate how to create a simple PHP_CodeSniffer rule that prohibits the use of # for single‑line comments.

Test code with violations:

<?php
# Check for valid contents.
if ($obj->contentsAreValid($array)) {
    $value = $obj->getValue();
    # Value needs to be an array.
    if (is_array($value) === false) {
        # Error.
        $obj->throwError();
        exit();
    }
}
?>

The PHP_CodeSniffer rule libraries reside in /src/Standards/ . To add a custom standard, create a new folder (e.g., FireLine ) with sub‑folders Sniffs and a ruleset.xml file.

Sample ruleset.xml :

<?xml version="1.0"?>
360 FireLine rule for test.

Inside Sniffs/Commenting/ create DisallowHashCommentsSniff.php implementing the Sniff interface. The class registers for T_COMMENT tokens and in process() checks whether the first character of the token content is # . If so, it adds an error message.

<?php
/**
 * This sniff prohibits the use of Perl style hash comments.
 */
namespace PHP_CodeSniffer\Standards\FireLine\Sniffs\Commenting;
use PHP_CodeSniffer\Sniffs\Sniff;
use PHP_CodeSniffer\Files\File;
class DisallowHashCommentsSniff implements Sniff {
    public function register() {
        return array(T_COMMENT);
    }
    public function process(File $phpcsFile, $stackPtr) {
        $tokens = $phpcsFile->getTokens();
        if ($tokens[$stackPtr]['content']{0} === '#') {
            $error = '禁止使用#号进行单行注释；扫描发现 %s';
            $data  = array(trim($tokens[$stackPtr]['content']));
            $phpcsFile->addError($error, $stackPtr, 'Found', $data);
        }
    }
}
?>

The register() method tells PHP_CodeSniffer to look for T_COMMENT tokens, which represent // , # , and /* */ comments. The process() method receives the file object and the token index, extracts the token content, and reports an error when a hash comment is found.

To run the custom standard, execute:

php D:/git/PHP_CodeSniffer/bin/phpcs \
    --standard=D:/git/PHP_CodeSniffer/src/Standards/FireLine \
    D:/git/PHP_CodeSniffer/src/Standards/FireLine/Tests \
    --report=xml --report-file=E:/RedlineReport/php_report01.xml

The generated XML report lists three errors, each corresponding to a hash comment in the test file, confirming that the custom rule works as intended.

<?xml version="1.0" encoding="UTF-8"?>
禁止使用#号进行注释；扫描发现 # Check for valid contents.
禁止使用#号进行注释；扫描发现 # Value needs to be an array.
禁止使用#号进行注释；扫描发现 # Error.

Thus, by following these steps you can extend PHP_CodeSniffer with your own coding‑standard rules and verify them through automated scans.